Vibration damping coating compositions are applied to automobile floor pans, deck lids and doors to damp or reduce road and engine noise and vibration. It is desirable that the sound damping coating be effective over a wide temperature range from −10 to 65° C. Most vibration damping compositions are effective over a relatively narrow temperature range, typically from 20 to 40° C.
For environmental reasons, aqueous coating compositions have been developed for such applications. However, since water is released from the coating composition upon drying or curing, the coating may shrink and may result in rough, uneven and cracked surfaces. Adjusting the filler content to improve appearance may adversely affect sound damping properties and/or adhesion of the coating composition to the substrate. Plasticizers may improve appearance, but performance in this regard is not consistent. Thus, there is a need in the art for an aqueous coating composition that exhibits sound damping properties over a broad temperature range and has good appearance.